<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <button type="">查看前后状态</button>
    <div>测试内容1</div>
    <input type="text" name="" value="测试内容2" class = "test2">

    <script src = "./jquery.min.js"></script>
    <script>
        $(function () {
            $("button").click(function () {
                //修改行间文本
                $("div").html("测试内容1已被改变");

                //修改文本内容
                $("input").text("测试内容2已被改变");
                
                //修改表单值
                $("input").val("测试内容2再次被改变");
            })
        })
    </script>
</body>
</html>